http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51812
Bug #: 51812 Summary: Virtual public inheritance leads to "undefined reference" in header files. Classification: Unclassified Product: gcc Version: 4.7.0 Status: UNCONFIRMED Severity: major Priority: P3 Component: c++ AssignedTo: unassig...@gcc.gnu.org ReportedBy: brede...@ucla.edu Created attachment 26292 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26292 The c++ file that has linker errors. Hi, Using gcc 4.7 causes new linker errors that are not present in e.g. 4.5, 4.6, or clang. These linker errors make it impossible to use header files that do not fully define some classes entirely in the header file. The errors look like: % g++-4.7 all5.C /tmp/ccfEMWL0.o: In function `Object::print() const': all5.C:(.text._ZNK6Object5printEv[_ZNK6Object5printEv]+0x58): undefined reference to `demangle(std::string const&)' /tmp/ccfEMWL0.o: In function `alphabet::compare(Object const&) const': all5.C:(.text._ZNK8alphabet7compareERK6Object[_ZNK8alphabet7compareERK6Object]+0x81): undefined reference to `typeinfo for alphabet' all5.C:(.text._ZNK8alphabet7compareERK6Object[_ZNK8alphabet7compareERK6Object]+0xa5): undefined reference to `operator==(alphabet const&, alphabet const&)' /tmp/ccfEMWL0.o: In function `alphabet::~alphabet()': all5.C:(.text._ZN8alphabetD1Ev[_ZN8alphabetD1Ev]+0xe): undefined reference to `vtable for alphabet' all5.C:(.text._ZN8alphabetD1Ev[_ZN8alphabetD1Ev]+0x26): undefined reference to `vtable for alphabet' /tmp/ccfEMWL0.o: In function `Triplets::Triplets(Triplets const&)': all5.C:(.text._ZN8TripletsC1ERKS_[_ZN8TripletsC1ERKS_]+0x3d): undefined reference to `VTT for Triplets' all5.C:(.text._ZN8TripletsC1ERKS_[_ZN8TripletsC1ERKS_]+0x51): undefined reference to `vtable for Triplets' all5.C:(.text._ZN8TripletsC1ERKS_[_ZN8TripletsC1ERKS_]+0x69): undefined reference to `vtable for Triplets' /tmp/ccfEMWL0.o:(.rodata._ZTV18AminoAcidsWithStop[_ZTV18AminoAcidsWithStop]+0x48): undefined reference to `alphabet::print() const' /tmp/ccfEMWL0.o:(.rodata._ZTV18AminoAcidsWithStop[_ZTV18AminoAcidsWithStop]+0x60): undefined reference to `alphabet::setup_letter_classes()' /tmp/ccfEMWL0.o:(.rodata._ZTV18AminoAcidsWithStop[_ZTV18AminoAcidsWithStop]+0x70): undefined reference to `alphabet::get_frequencies_from_counts(std::valarray<double> const&, double) const' /tmp/ccfEMWL0.o:(.rodata._ZTC18AminoAcidsWithStop0_10AminoAcids[_ZTV18AminoAcidsWithStop]+0x48): undefined reference to `alphabet::print() const' /tmp/ccfEMWL0.o:(.rodata._ZTC18AminoAcidsWithStop0_10AminoAcids[_ZTV18AminoAcidsWithStop]+0x60): undefined reference to `alphabet::setup_letter_classes()' /tmp/ccfEMWL0.o:(.rodata._ZTC18AminoAcidsWithStop0_10AminoAcids[_ZTV18AminoAcidsWithStop]+0x70): undefined reference to `alphabet::get_frequencies_from_counts(std::valarray<double> const&, double) const' /tmp/ccfEMWL0.o:(.rodata._ZTC18AminoAcidsWithStop0_8alphabet[_ZTV18AminoAcidsWithStop]+0x30): undefined reference to `typeinfo for alphabet' /tmp/ccfEMWL0.o:(.rodata._ZTC18AminoAcidsWithStop0_8alphabet[_ZTV18AminoAcidsWithStop]+0x48): undefined reference to `alphabet::print() const' /tmp/ccfEMWL0.o:(.rodata._ZTC18AminoAcidsWithStop0_8alphabet[_ZTV18AminoAcidsWithStop]+0x60): undefined reference to `alphabet::setup_letter_classes()' /tmp/ccfEMWL0.o:(.rodata._ZTC18AminoAcidsWithStop0_8alphabet[_ZTV18AminoAcidsWithStop]+0x70): undefined reference to `alphabet::get_frequencies_from_counts(std::valarray<double> const&, double) const' /tmp/ccfEMWL0.o:(.rodata._ZTV10AminoAcids[_ZTV10AminoAcids]+0x48): undefined reference to `alphabet::print() const' /tmp/ccfEMWL0.o:(.rodata._ZTV10AminoAcids[_ZTV10AminoAcids]+0x60): undefined reference to `alphabet::setup_letter_classes()' /tmp/ccfEMWL0.o:(.rodata._ZTV10AminoAcids[_ZTV10AminoAcids]+0x70): undefined reference to `alphabet::get_frequencies_from_counts(std::valarray<double> const&, double) const' /tmp/ccfEMWL0.o:(.rodata._ZTC10AminoAcids0_8alphabet[_ZTV10AminoAcids]+0x30): undefined reference to `typeinfo for alphabet' /tmp/ccfEMWL0.o:(.rodata._ZTC10AminoAcids0_8alphabet[_ZTV10AminoAcids]+0x48): undefined reference to `alphabet::print() const' /tmp/ccfEMWL0.o:(.rodata._ZTC10AminoAcids0_8alphabet[_ZTV10AminoAcids]+0x60): undefined reference to `alphabet::setup_letter_classes()' /tmp/ccfEMWL0.o:(.rodata._ZTC10AminoAcids0_8alphabet[_ZTV10AminoAcids]+0x70): undefined reference to `alphabet::get_frequencies_from_counts(std::valarray<double> const&, double) const' /tmp/ccfEMWL0.o:(.rodata._ZTV3RNA[_ZTV3RNA]+0x48): undefined reference to `alphabet::print() const' /tmp/ccfEMWL0.o:(.rodata._ZTV3RNA[_ZTV3RNA]+0x60): undefined reference to `alphabet::setup_letter_classes()' /tmp/ccfEMWL0.o:(.rodata._ZTV3RNA[_ZTV3RNA]+0x70): undefined reference to `alphabet::get_frequencies_from_counts(std::valarray<double> const&, double) const' /tmp/ccfEMWL0.o:(.rodata._ZTC3RNA0_11Nucleotides[_ZTV3RNA]+0x48): undefined reference to `alphabet::print() const' /tmp/ccfEMWL0.o:(.rodata._ZTC3RNA0_11Nucleotides[_ZTV3RNA]+0x60): undefined reference to `alphabet::setup_letter_classes()' /tmp/ccfEMWL0.o:(.rodata._ZTC3RNA0_11Nucleotides[_ZTV3RNA]+0x70): undefined reference to `alphabet::get_frequencies_from_counts(std::valarray<double> const&, double) const' /tmp/ccfEMWL0.o:(.rodata._ZTC3RNA0_8alphabet[_ZTV3RNA]+0x30): undefined reference to `typeinfo for alphabet' /tmp/ccfEMWL0.o:(.rodata._ZTC3RNA0_8alphabet[_ZTV3RNA]+0x48): undefined reference to `alphabet::print() const' /tmp/ccfEMWL0.o:(.rodata._ZTC3RNA0_8alphabet[_ZTV3RNA]+0x60): undefined reference to `alphabet::setup_letter_classes()' /tmp/ccfEMWL0.o:(.rodata._ZTC3RNA0_8alphabet[_ZTV3RNA]+0x70): undefined reference to `alphabet::get_frequencies_from_counts(std::valarray<double> const&, double) const' /tmp/ccfEMWL0.o:(.rodata._ZTV3DNA[_ZTV3DNA]+0x48): undefined reference to `alphabet::print() const' /tmp/ccfEMWL0.o:(.rodata._ZTV3DNA[_ZTV3DNA]+0x60): undefined reference to `alphabet::setup_letter_classes()' /tmp/ccfEMWL0.o:(.rodata._ZTV3DNA[_ZTV3DNA]+0x70): undefined reference to `alphabet::get_frequencies_from_counts(std::valarray<double> const&, double) const' /tmp/ccfEMWL0.o:(.rodata._ZTC3DNA0_11Nucleotides[_ZTV3DNA]+0x48): undefined reference to `alphabet::print() const' /tmp/ccfEMWL0.o:(.rodata._ZTC3DNA0_11Nucleotides[_ZTV3DNA]+0x60): undefined reference to `alphabet::setup_letter_classes()' /tmp/ccfEMWL0.o:(.rodata._ZTC3DNA0_11Nucleotides[_ZTV3DNA]+0x70): undefined reference to `alphabet::get_frequencies_from_counts(std::valarray<double> const&, double) const' /tmp/ccfEMWL0.o:(.rodata._ZTC3DNA0_8alphabet[_ZTV3DNA]+0x30): undefined reference to `typeinfo for alphabet' /tmp/ccfEMWL0.o:(.rodata._ZTC3DNA0_8alphabet[_ZTV3DNA]+0x48): undefined reference to `alphabet::print() const' /tmp/ccfEMWL0.o:(.rodata._ZTC3DNA0_8alphabet[_ZTV3DNA]+0x60): undefined reference to `alphabet::setup_letter_classes()' /tmp/ccfEMWL0.o:(.rodata._ZTC3DNA0_8alphabet[_ZTV3DNA]+0x70): undefined reference to `alphabet::get_frequencies_from_counts(std::valarray<double> const&, double) const' /tmp/ccfEMWL0.o:(.rodata._ZTV11Nucleotides[_ZTV11Nucleotides]+0x48): undefined reference to `alphabet::print() const' /tmp/ccfEMWL0.o:(.rodata._ZTV11Nucleotides[_ZTV11Nucleotides]+0x60): undefined reference to `alphabet::setup_letter_classes()' /tmp/ccfEMWL0.o:(.rodata._ZTV11Nucleotides[_ZTV11Nucleotides]+0x70): undefined reference to `alphabet::get_frequencies_from_counts(std::valarray<double> const&, double) const' /tmp/ccfEMWL0.o:(.rodata._ZTC11Nucleotides0_8alphabet[_ZTV11Nucleotides]+0x30): undefined reference to `typeinfo for alphabet' /tmp/ccfEMWL0.o:(.rodata._ZTC11Nucleotides0_8alphabet[_ZTV11Nucleotides]+0x48): undefined reference to `alphabet::print() const' /tmp/ccfEMWL0.o:(.rodata._ZTC11Nucleotides0_8alphabet[_ZTV11Nucleotides]+0x60): undefined reference to `alphabet::setup_letter_classes()' /tmp/ccfEMWL0.o:(.rodata._ZTC11Nucleotides0_8alphabet[_ZTV11Nucleotides]+0x70): undefined reference to `alphabet::get_frequencies_from_counts(std::valarray<double> const&, double) const' /tmp/ccfEMWL0.o:(.rodata._ZTI10AminoAcids[_ZTI10AminoAcids]+0x10): undefined reference to `typeinfo for alphabet' /tmp/ccfEMWL0.o:(.rodata._ZTI11Nucleotides[_ZTI11Nucleotides]+0x10): undefined reference to `typeinfo for alphabet' collect2: error: ld returned 1 exit status All the errors go away if you change class alphabet to not have virtual public inheritance, by removing the word "virtual".